Supplemental restraint devices have become commonplace in vehicles in recent years and engineering and design efforts have increasingly focused on such devices deployable along vehicles' interior sides. In the event of a side impact or vehicle rollover event, a curtain or inflatable cushion is rapidly positioned between the vehicle passenger and the window/door of the vehicle. Due to the limited vehicle structure that separates an occupant from a rapidly moving body impacting the side of the vehicle, occupants may sustain much greater injuries in side-impact events than front or rear impacts. The energy absorbed by the vehicle structure tends to be substantially less than the energy which may be absorbed in front-end or rear-end collisions. Moreover, the forces generated in side-impact or vehicle rollover events may actually cause the occupant to be ejected from the side of the vehicle. Some vehicles, due to their structure as well as a possible increased rollover risk, present particular problems in this area.
Various mounting methods and restraint apparatus configurations have been developed to assist in protecting occupants during such events. One approach has been to position a deflated or folded restraint cushion or curtain behind a trim panel located along the vehicle roof rail. When deployment is desired, the deploying restraint can burst through or push aside the trim panel, ultimately being positioned adjacent the occupant, where it absorbs impact from the occupant's head and torso. Where inflatable cushions are used, however, the necessarily rapid rate of inflation, coupled with the consequences of an occupant striking the deployed cushion, can sometimes present difficulties to maintaining the cushion between the occupant and the window/door of the vehicle. For example, an initial striking of the cushion by the occupant may cause the cushion to bounce out of its operative position, creating a risk that the occupant could strike the window or door upon being thrown toward the door a second time. In a severe crash, where a vehicle rolls multiple times, this scenario may present multiple opportunities for the occupant's injury. In addition to the problems of maintaining the cushion in an operative position throughout an accident sequence, the impact of an occupant on the cushion may actually displace the cushion through the vehicle window. Maintaining the effective position of the side airbag has proven challenging. Accordingly, engineers have developed a variety of tethering and mounting schemes to support the cushion during deployment. Many of these systems, however, are relatively complex and bulky. In addition, the rigid components can be difficult to package in the limited space available behind a trim panel.